Types of Drill Bits

1. Brad Point Bits for Wood

There are three main types of wood drill bits, they are characterized by the small point at the tip of the bit. Spurs on either side of the point will cut clean, straight holes. They are suitable for all types of wood and available in a huge range of sizes and lengths.

2. Auger Drill Bits

These types of bits cut large, deep accurate holes. The spiraling shaft comes to a fine, threaded point. Carbon-steel bits are best and it can be resharpened easily.

3. Wood Spade or Paddle Bits

The pointed tip begins the hole and the paddle-shaped blade bores wide, large holes. The size is clearly displayed on the paddle's face.

4. Metal Drill Bits

These are called high-speed steel (HSS) bits and are characterized by their black color. These are expensive, durable ones may contain cobalt or be titanium-coated. They can also be used on wood or plastic, but they last longer if reserved for metalwork.

5. Masonry Drill Bits

This type of bits can cut into many masonry surfaces. The shaft spirals up to a tip that is often composed of an extra-hardened material. Bit colors are different because of different materials used. The tip may be a different color from the shaft due to a hardened coating. For instance, a chrome-vanadium shaft may be finished with a tungsten-carbide tip.

6. SDS Bits

There is a wide range of special bits available which are made for a specific task, or to fit a particular type of chuck. These are made specifically to fit an SDS chuck mechanism, and will not work with any other chuck. The end that fits into the chuck has a fluted appearance and the drilling part of the shaft is normal.

7. Countersink Bits

These bits are used to cut a space for screw heads. They are ideal for preventing wood from splitting.

8. Tile and Glass Bits

This is spear-shaped tungsten-carbide tip which penetrates a tile or piece of glass and then enlarges the hole to the diameter of the tip's base.

9. Flexible Bit and Hole Cutter

A flexible drill shaft (left) attaches to the chuck and allows it to drill in an inaccessible area. It cannot be used with the drill in reverse action. A hole cutter bit sometimes also called a hole-saw. It comes in various sizes for cutting wood and metal. First drill bit cuts the piece, then the round cutter makes a larger hole.

10. Flat-Head Screwdriver Bits

Some bits insert directly into the chuck, but most need to be put in a bit holder, which is then inserted into the chuck. These are made for use with slot-headed screws.